I thought you might be interested to hear the outcome of the load development I have been doing with my light 1000yd bench gun. This rifle formally wore a Shilen barrel in 6/284, but since I have been seeing such great success with the 6.5 bore, I decided to go to a 6.5mm for competition and serious long range shooting. I asked my gunsmith to get a Madco (Australian premium barrel maker) 6.5mm in 1/8” twist. He then chambered this in 6.5x57 Imp. Using fire-formed RWS cases, fully prepped and neck turned, the case capacity is 62.5 gns of water. I decided on this chambering for a number of reasons:
I have had very good results from the 6.5/284, but cases remain an issue (go Lapua!).
Case capacities of around 62gns seem to perform very well in the 6.5mm bore.
I had 200 virgin RWS 7x57 cases on hand.
Dies were easily available by ordering Redding 257 Roberts AI “S” type neck and FL dies, then adding a .290 neck bushing (chamber is a .293 neck). Seating is achieved by running the chamber die into a Wilson 6.5x55 in-line die.
I took delivery of this barrel with a very limited time for load development. I concentrated on the Lapua 139gn bullet because the 105gn Lapua had worked well in my 6/284 and because Lapua bullets are easily available locally. My results from a resent competition were encouraging, however I was keen to try more load/bullet combo’s. Subsequent testing has shown the Lapua bullets to be the worst performers IN THIS RIFLE. I have had much better results on a consistent basis with the 140gn Amax and the 142gn Matchking. This last weekend I concentrated on getting a load finalised with the 140gn Amax. I kept getting 4 shots in about .3” at 100 yards, but with a 5th shot dropping out below the rest of the group and opening it up to about 1.0” in total. When I got back from the range, I took the couple of hundred Amax bullets I had on hand and started ogive checking them. The results showed two batches, one averaging about 1.422” and another at around 1.522”. I expect this batching will eliminate the flyer shots.
I briefly tried H4350 (ADI AR2209), H1000 (ADI , N160 and RL22, but generally achieved best results with H4831 with all bullets. Velocities run from around 2800 fps to 2950 fps. The following 5 shot groups were shot at 100 yards in fairly mild wind.
This is the best group I have ever gotten from Lapua 139gn bullets.
This group is from Sierra 142gn bullets.
This group is with 140gn Amax bullets
Another group with 140gn Amax.
I don’t have a current photo with the new barrel, but this is the rifle with the 6/284.